Heavy duty liquid detergent compositions



HEAVY DUTY LIQUID DETERGENT COMPOSITIONS ,William Ralph Hearn, Scarboro,Ontario, Allister Neil MacLean,and Frederick William Trnsler, Toronto,Ontario, Canada, assignors to Colgate-Palmoiive :Company, JerseyCity,.N.J., a corporation of Delaware No Drawing. Application September6, 1955 Serial No. 532,733

19 Claims. (Cl. 252-137) The presentinvention relates to a heavy dutyliquid detergent composition in the form of a stable, free-flowingsuspension having thixotropic properties.

Various types of liquid compositions in the form of lotions and liquidemulsions are known in thecosmetic art, including shampoo products. Suchcompositions comprise generally a suitable detergent and an opacifier,stabilizing agent or suitable waxy material in an aqueous solvent. Wheresoap is the detergent in a shampoo, it has been suggested to incorporatea very small amount of a water-softener such as various phosphatecompounds in order to prevent formation of insoluble soaps during use ofthe product in hard water.

In the detergent art, however, it has been common practice to preparedetergent compositions in powdered form, as obtained by spray-drying aslurry of the detergent composition for example. In these powderedproducts, alkaline builder salts such as sodiumytripolyphosphate andpyrophosphate have been incorporated in significant amounts to improvethe detergency or washing power for the laundering of soiled textilematerials. Other salts such as sodium silicate, carbonate,carboxymethylcellulose and the like have been employed also in thepreparation of powdered heavy duty detergentcompositions.

Within recent years, liquid detergent compositions having particularutility for washing of dishes and finefabrics have been producedcommercially. In general, such light-duty liquid compositionshave beenprimarily a clear solution of a suitable detergent in an aqueoussolvent.

Heretofore, heavy duty detergent compositions in liquid, free-flowingform have not been made as articles of commerce because of thedifiiculty in retaining substantial proportions of the ingredients insolution. For. example, the mere admixture of substantial amounts ofphosphate salts and an organic detergent in water results in a markedtendency for separation of the mixture into two or more immisciblephases, sometimes with the settling of :the-

phosphate salts ashard non-redispersible cakes in the bottom of thecontainer.

It has now been found thatefiective amounts of alkaline builder salts,such as sodium tripolyphosphate and/or tetrasodium pyrophosphate, can beincorporated and formed into a stable, free-flowing heavy duty liquiddetergent composition by a careful choice of ingredients and theirproportions, as hereinafter described and claimed.

In accordance with the present invention, such a heavy duty liquiddetergent composition comprises a watersoluble organic synetheticdetergent and water-soluble inorganic alkaline builder salt,particularly polyphosphate salt, in an aqueous alcoholic medium, theamount of said inorganic salt being in excess of its normal solubilityin the amount of water present and maintained in a permanentlynon-caking suspension inthe presence of minor proportions of a waxsubstantially insoluble in water and in the aqueous-alcoholic solvent ofthecompositions, a

substantially water-insoluble colloidal material, and a water-solublenitrogen compound selected from the group 2,920,045 Patented- Jan. s,1960 2 consisting of urea and'thiourea. By reference to a stable ornon-caking suspension, it is meant that the undissolved ingredients areessentially retained in'the product in suspension or are re-dispersibleupon light shaking.

These novel liquid detergent compositions are characterized by manydesirable properties. The product is in the form of a substantiallyhomogeneous 'opaque suspension which exhibits a satisfactory degree ofstability upon aging.

saltsduring storage life of the composition. By virtue of thisthixotropy and other peculiar physical properties,-

the composition has suflicient viscosity, when at rest, to maintain theingredients and particularly the dispersed alkaline builder salts inhomogeneous suspension, but the composition becomes highlyfluidiuponlighcshaking and may be poured freely fromzthe container. wln additionthe composition exhibits a washing power during launder-v ing thatiscomparable to thetco'mmercialheavy-duty detergents in powdered form.

-In the formulation of such product, the ingredients should beselected-and proportionedso as to form a suspension having the foregoingqualities. As indicated the suspension-is free-flowing uponlight-shaking of the container at room temperature. sion may be variedaccordingly but the product should have an apparent viscosity from about50 to about 5000 centipoises and preferably about 500 to' about 3000centipoises, for optimum results. The above references to viscosity andany others set forth in this application are determined by a Brookfieldviscometer,;Model HAF, using a No. 2 spindle at 10 r.p.m. and atroomtemperature, i.e. 20 C. The suspension may be employed in .any suitablecontainer or packaging material :such as metal, glass or plastic in theform of bottles, cans, drums or bags;

For the sake of simplicity, the, several. ingredients will be describedindividually to-some extentbut the final ,desired qualities of theproduct are the resultant or unitary effects produced by theinter-action of the ingredients:

within the indicated proportions.

These -.novel compositions contain an .organic detergent selected from,the a group consisting of 'the *watergent, particularly thosehavin'gabout '8 to 15 carbon atoms in the alkyl group. It ispreferredto-use'the higher alkyl benzene sulfonate detergent-for optimum effects,though other similar detergents having a mononuclear aryl nucleus, suchas toluene,-xy1ene,lor phenol, may 'be used also.- The higher alkylsubstituent on the aromatic nucleus may be branched or straight-chainedin structure, examples of suchgroup being nonyl, dodecyl and pentadecylgroups derived from polymers'of'lower'm'onoolefins, decyl, keryl, andthe like.

Examples of suitable aliphatic detergents are the normal and secondaryhigher alkyl sulfate detergents, particularly those having about 8 to 15carbons in the fatty alcohol residue, such as-lauryl (or coconut fattyalcohol) sulfate.

Other suitable detergents are the sulfuric acid esters of polyhydric.alcohols incompletely ,esterified with higher fatty acids, -e.g.coeonut.-'oil monog'lyceride'monosulfate; the higher fatty 'acid estersof low .molecular'weight" alkylolsulfonic acids, -e.g. oleic .acid.ester of" isethionic acids, e.g. lauric acid amide of taurine; and thelike.

It exhibits thixotropicl properties which assure suspension of thedense, substantially undissolved builder The'viscosity of the suspenformof their water-soluble salts, suchas the alkali metal andnitrogen-containing, e.g. lower alkylolamine, salts. Examples are thesodium, potassium, ammonium, isopropanolamine; monoand t'ri-ethanolaminesalts of said higher alkyl benzene sulfonate, higher alkyl sulfate andthe like. In commercial practice, it is preferred to use the alkalimetal salts.

Examples of suitable non-ionic detergents are the water-solublenon-ionic polyalkylene oxide detergents. In general, these detergentsare the products produced by the introduction of a controlled number ofalkylene oxide groups into an organic hydrophobic compound or group,usually of an aliphatic or aromatic structure. The hydrophobic organicgroup contains usually at least about 8 carbons, and preferably up to 30carbons, condensed with at least about 5 and usuallyup :to about-5Oalkylene oxide groups. It is preferred to use the polyoxyethylenecondensates derived from ethylene oxide, although other lower alkyleneoxides such aspropylene oxide, butylene oxide and the like havegenerally similar properties and may be substituted therefor.

Among the non-ionic detergents, it is preferred to use the polyalkyleneoxide condensates of alkyl phenol, such as the polyoxyethylene ethers ofalkyl phenols having an alkyl group of at least about six, and usuallyabout 8 to 12 carbons, and an ethylene oxide ratio (No. of moles perphenol) of about 7.5, 8.5, 11.5 and 20, though the number of ethyleneoxide groups will be usually from about 8 to 18. .Thev alkyl substituenton the aromatic nucleus may be di-isobutylene, diamyl, polymerizedpropylene, dimerized C -C olefin, and the like. 7

Further suitable detergents are the polyoxyalkylene esters of organicacids, such as the higher fatty acids, rosin acids, tall oil acids, oracids from the oxidation of petroleum, etc. These polyglycol esters willcontain usually from about 12 to about 30 moles of ethylene oxide or itsequivalent and about 8 to 22 carbons in the acyl group. Suitableproducts are refined tall oil condensed with 16 or 20 ethylene oxidegroups, or similar polyglycol esters of lauric, stearic, oleic acids,etc.

Additional non-ionic agents are the polyalkylene oxide condensates withhigher fatty acid amides, such as the higher fatty acid primary amides,monoand di-ethanolamides. Suitable agents are coconut fatty acid amidecondensed with about 10 to 50 moles of ethylene oxide.

The fatty acyl group will have similarly about 8 to 22 carbons, andusually about 10 to 18 carbon atoms, in such products. The correspondingsulfonamides may be used also if desired.

Other suitable polyether non-ionic detergents are the polyalkylene oxideethers of higher aliphatic alcohols. Suitable fatty alcohols having ahydrophobic character, preferably 8 to 22 carbons, are lauryl, myristyl,cetyl, stearyl and oleyl alcohols which may be condensed with anappropriate amount of ethylene oxide, such as at least about 6, andpreferably about 10-30 moles. A typical product is oleyl alcoholcondensed with about 12, 15, or 20 moles of ethylene oxide. Thecorresponding higher alkyl mercaptans or thioalcohols condensed withethylene oxide are suitable in the present invention also. Thewater-soluble polyoxyethylene condensates with hydrophobicpolyoxypropylene glycols may be employed also.

Further suitable non-ionic detersive materials are the higher fatty acidalkanolamides, such as the monoethanolamides, diethanolamides andisopropanolamides wherein the acyl radical has about 10 to 14 carbonatoms. Examples are coconut (or equivalent lauric), capric and. myristicdiethanolamide, mono-ethanolamide and isopropanolamide. As part of theireffects, the alkanolamide materials function to improve the foamingpower and detergeucy of the compositions and aid also in the obtentionof the desired liquids in a more stable form. These materials areemployed preferably in an amount. from about 1 to 15% by weight in thesuspension.

' Theproportion of organic detergent material in the final compositionis variable to some extent but it has been found that amounts from about5 to about 30%, preferably about 10-25%, by weight are highlysatisfactory with respect to both the physical appearance andperformance of the product.'

Any water-soluble alkaline builder salts may be used but it is preferredto employ the inorganic polyphosphate salts. Such polyphosphatematerials have the property of inhibiting precipitation of calcium andmagnesium material in aqueous solution and may be considered as derivedfrom orthophosphoric acid or the like by the removal of water. Thesecomplex or molecularly dehydrated-polyphosphate salts may be used in theform of the normal or completely neutralized salt, e.g. sodiumtripolyphosphate, or the partially neutralized salt, e.g. sodium acidtripolyphosphate. It is preferred to employ the alkali metalpolyphosphate, and particularly a sodium tripolyphosphate or a sodiumpyrophosphate for optimum efliects. Other suitable polyphosphatematerials are potassium tripolyphosphate, tetrapotassium pyrophosphate,sodium hexametaphosphate, hexasodium hexametaphosphate, hexasodiumtetraphosphate and tetrasodium pyrophosphate. Examples of other alkalinebuilder salts which may be employed are sodium orthophosphate, e.g.trisodium phosphate, soda ash, borax, and the like.

The alkaline builder salts should be employed in sub stantial amountsuch that the addition of a small portion of the liquid product to awashing bath will result in effective detergeucy and washing power. Ithas been found that it is possible to maintain in homogeneous suspensionamounts of builder salts from about 15 to 45%, and preferably about 20to 40%, by weight of the composition as formulated. In the presentinvention, such materials are present in amounts in excess of theirsolubility in the amount of water present in the product but,nevertheless, the excess is maintained in the form of dispersed orundissolved particles in substantially homogeneous suspension. Forexample, anhydrous sodium tripolyphosphate has a solubility at roomtemperature of the order of about 15% in water. In the liquid product,sodium tripolyphosphate or pyrophosphate may be incorporated in amountsas much as about fifty times, preferably about 10 to about 25 times itsnormal solubility in the amount of water present, even though theproduct contains alcohol as part of the solvent medium which tends todepress the solubility of the polyphosphate materal.

For the obtention of a product having the desired physical properties,it is essential to incorporate minor proportions of a wax which issubstantially insoluble in Water and in the aqueous-alcoholic solvent ofthe compositions; a substantially water-insoluble collodial material;and urea or thiourea. The quantities of these essential ingredients maybe varied to some extent, depending upon the specific material used, andupon the viscosity desired for the finished composition.

The wax or wax-like substance, preferably hydrogenated castor oil, isemployed usually in proportions from about 0.10% to about 1% by weight.Other suitable wax (including wax-like) substances are the naturallyoccurring waxes which consist essentially of esters of high molecularweight monohydric alcohols and higher fatty acids. Of the naturallyoccurring Waxes, carnauba is particularly effective, although othersincluding candelilla, montan and beeswax may also be used. Waxes fromthe class including ozokerite, ceresin and microcrystalline waxes alsoare suitable, as are synthetic wax-like substances including the estersof the higher fatty acid alkanolamides, e.g. the stearyl ester ofstearic monoethanolamide and the lauryl ester of the monoethanolamide ofhydrogenated castor oil. Higher fatty acids, fatty alcohols and fattyacid amides having more than 18 carbon atoms which are Wax-likematerials may be used also. In general, these materials may be usedindividually' orin any suitable mixture? Ithasbeenfound thatparticularly effective products are obtained' 'using.

water, it is preferred to use bentonite in amounts of-15% but othercolloidal'clays and the like may be used also.

Othersuitable-materials are colloidal silica; 'rna' gnesium silicate,aluminum-magnesium silica gel (e.g. Veegum) and "the likel' Thesematerials may be used individually or-in'any suitable mixture;If'desired, the siliceous ma terial may be substitutedin Whole or partby polyvalent metal soaps; such "as the heavy metal and alkaline earthmetal salts of higher fattyacids, e.g. zinc, 'calcium'or' magnesiumsoaps of coconut,-tallow or stearic fatty-acids which are colloidallydispersible also. The polyvalent metal soaps maybe used to advantageWith-the inorganic siliceous materials in preferred amounts from about0.1 to about 4% of the total compositions.

The inclusion of urea or thiourea as indicated aids vitalily in theproduction of suspensions havingthixotropic properties and easilypourable viscosity. In the absence of the ureas, the compositions tendto form stiff, unpourable, irreversible gels. Any suitable amount ofurea or thiourea may be employed, but it is usuallto employ at leastabout 2% and preferably about 5 to 20% by weight of the formulation.

The aqueous alcoholic, solvent is an essential considerationalso. Ingenerahthe' alcohol 'iswater-imiscible such as the saturated loweraliphatic monohydric. alcohols. Suitable examples are ethyl, propyl andisopropyl alcohol. The proportions of water andalcohol may be variedfor-optimum viscosity and stability for each preparation. It hasbeenfound that superior products may be formed having a solids contentfrom about 60 to 90% and an aqueous alcoholcontent from about to 40%,preferably -25%, by weight of the formulation. Suitable proportions ofwater and alcohol may be selected from the range of about 520%,preferably 5-15% water and 520%, preferably 515% alcohol by Weight. Inan 'excessive amount of alcohol is used the thixotropy of the,

compositions. is impaired and the phosphate materials tend tosettle andform a cake which is not readily redispersible in the liquid. Uponproportioning of the essential ingredients, the suspension is fairlyviscous and stable without any apparent or significant tendency toseparation. Upon shaking .in a bottle, it does not foam but drainsevenly, quickly permitting pouring of uniform portions of the product.The agitation of the viscous product by shaking'converts the systemtoa-highly fluid-mixture which flows freely. It dissolves readily uponaddition of small'portions to a laundering bath and exhibits a highdegree of washing power.

Various other ingredients may be added as desired :including compatibleperfumes, coloring materials, .corrosion or anti-tarnishing inhibitors,germicides, hydrotropes, bleaching agents; optical bleaches orfluorescent brighteners, and the like. It is preferred to add -a minortion agent, e.g. cellulose ethers.

carboxymethylcellulose.

The following examples are, additionally illustrative of the nature ofthe invention and it will be understood that the invention is notlimited thereto. All parts are by weight unless otherwise specified.

' Example I The following formulation results in a satisfactory Ingeneral, they may be used 'in' amounts bleach.

Example IV Percent Nonyl phenol ethylene oxide condensate (Antarox-A400) 120.00 Ethyl alcohol 15.00 Water. 10.00 Fully hydrogenated castor-oil- 0.40 Sodium tripolyphosphate 35.00 Bentonite 4.00 Sodium.carboxmethylcellulose 1.50- Urea; I 13.34

e heavy-duty liquid detergent composition in homogeneous suspension:

Ingredient: Percent sodium tripolyphosphate 35.0 Sodium"dodecyl-benzene'sulfonate 15.0

Nonyl phenolethyleneoxide" condensate (Antarox A400) 5.0 Coconutdiethanolamide 5.0 Hydrogenatedcastor oil 0.4 Urea 14.0 Bentonite 4.0Sodium carboxymethylcellulo'se a 1.5 Ethyl-alcohol 10.0 Water 9.1

the balance being minor amounts of perfume, coloring material, opticalbleach "and corrosion inhibitor.

Thissuspension is prepared by the preferred method whereby sodiumdodecylbenzene sulfonate which is substantiallyfree of inorganic salts,the Antarox A400 andthe coconut diethanolamide are mixed in the waterand ethanol. The castor wax is melted and added tothe deter-- gent"solution with mixing. The remaining ingredients are added individuallywith stirring to form a substantial-.' -ly uniform andhomogeneous-mixture. The final product has a viscosity of about 1400centipoises.

A similar product having about 10.4% Water and-9.9%

alcohol has a viscosity of about=700 centipoises.

Example II Percent Sodiurrr-lauryl sulfate 25.00 Ethyl alcohol 12.00-Water 10.00 Fully hydrogenated castor oil 0.40 Sodium. tripolyphosphateV 35.00 Bentonite v -1. 4.00 Urea 13.60

100.00 Example III Percent- Sodiumdodecyl benzene sulfonate 20.00 Ethylalcohol 15.00 Water 10:00 Fullyhydrogenated castor oil 0.40 Sodiumtripolyphosphate 35.00 Bentonite 4.00 Sodium carboxymethylcellulose 1.50Urea 13.89

the balance being .minor. amounts of perfumeand optical materialand'optical bleach.

the balance being minor amounts of perfume, coloring material andoptical bleach.

Example VI Percent Sodium dodecyl benzene sulfonate 15.00

Nonyl phenol ethylene oxide condensate (Antarox A400) 5.00 Coconutdiethanolamide 5.00 Ethyl alcohol 15.00 Water 10.00 Fully hydrogenatedcastor oil 0.40 Soda ash 35.00 Bentonite 4.00 Sodiumcarboxymethylcellulose 1.50 Urea 8.34

the balance being minor amounts of perfume, coloring material andoptical bleach.

Although the present invention has been described and illustrated with areference to specific examples, it is understood that modifications andvariations of composition and procedure are contemplated within thescope of the appended claims.

Having thus described the invention, what is claimed is:

1. A liquid detergent composition in the form of a stable, free-flowingsuspension having thixotropic properties which consists essentially ofabout to 30% by weight of a water-soluble detergent selected from thegroup consisting of the water-soluble anionic organic sulfate andsulfonate, and non-ionic organic detergents; and about 15 to 45% byweight of a'water-soluble inorganic alkaline builder salt in an aqueousalcoholic medium containing about 5 to 20% by weight of a water-misciblesaturated lower aliphatic monohydric alcohol, the'amount of saidinorganic salt being in excess of its normal solubility in the amount ofwater present and maintained in a permanently non-caking suspension inthe presence. of about 0.1 to 1% by weight of a substantially water-insoluble wax, about 0.1 to by weight of a substantially water-insolublematerial selected from the group consisting of inorganic colloidalsilicates, colloidal silica. and polyvalent metal soaps of higher fattyacids; and about 2 to 20% by weight of a water-soluble nitrogen compoundselected from the group consisting of urea and thiourea.

2. A liquid detergent composition in accordance with claim 1 wherein thepolyvalent metal soap is polyvalent metal stearate.

3. A liquid detergent composition in the form of a stable, free-flowingsuspension having thixotropic properties which consists essentially ofabout 5 to 30% by weight of a water-soluble detergent selected from thegroup consisting of a water-soluble anionic organic sulfate andsulfonate, and non-ionic organic detergents; and about 15 phate salt inan aqueous alcoholic medium containing about 5 to 20% by weight of awater-miscible saturated lower aliphatic monohydric alcohol, the amountof said polyphosphate salt being in excess of its normal solubility inthe amount'of water present and maintained in a permanently non-cakingsuspension in the presence of about 0.1 to 1% by weight of asubstantially water-insoluble wax, about 0.1 to 10% by weight of asubstantially Water-insoluble inorganic colloidal silicate, and about 2to 20% by Weight of a water-soluble nitrogen compound selected from thegroup consisting of urea and thiourea.

4. A liquid detergent composition in accordance with claim 3 wherein thepolyphosphate salt is sodium tripolyphosphate.

5. A liquid detergent composition in accordance with claim 3 wherein thepolyphosphate salt is sodium pyrophosphate.

6. A liquid detergent composition in accordance with claim 3 wherein thedetergent is a water-soluble higher alkyl benzene sulfonate detergent.

7. A liquid detergent composition in accordance with claim 3 wherein thedetergent is a water-soluble higher alkyl sulfate detergent.

8. A liquid detergent composition in accordance with claim 3 wherein thedetergent is a water-soluble higher alkyl phenol condensate withethylene oxide.

9. A liquid detergent composition in accordance with claim 3 whichcontains hydrogenated castor oil.

10. A liquid detergent composition in accordance with claim 3 whereinthe wax is carnauba wax.

11. A liquid detergent composition in accordance with claim 3 whereinthe inorganic colloidal silicate is bentonite.

12. A liquid detergent composition in accordance with claim 3 whereinthe nitrogen compound is urea.

13. A liquid detergent composition in the form of a stable,free-flowing, substantially homogeneous suspension having thioxotropicproperties which consists essentially of about 5 to 30% by weight of awater-soluble detergent selected from the group consisting of thewatersoluble anionic organic sulfate and sulfonate, and nonionic organicdetergents; about 15 to 45 by weight of Water-soluble inorganicpolyphosphate salt in an aqueous ethanol medium containing about 5 to20% by weight of ethanol, the amount of said polyphosphate being inexcess of its normal solubility in the amount of water present andmaintained in a permanently non-caking suspension in the presence ofabout 0.1 to 1% by weight of hydrogenated castor oil, about 1 to 5% byweight of bentonite and about 5 to 20% by weight of urea.

14. A liquid detergent composition in the form of a stable, free-flowingsuspension in accordance with claim 13 which contains about 1 to 15% byweight of a higher fatty acid alkanolamide.

15. A liquid detergent composition in the form of a stable,free-flowing, substantially homogeneous suspension having thixotropicproperties which consists essentially of about 5 to 30% by weight of adetergent selected from the group consisting of water-soluble anionicorganic sulfate and sulfonate, and non-ionic organic detergents; andabout 15 to 45% by weight of sodium tri polyphosphate in about 10 to 40%by weight of an aqueous ethanol medium containing about 5 to 20%ethanol, the amount of tripolyphosphate being from about 10 to about 25times its normal solubility in the amount of water present andmaintained in a permanently noncaking suspension in the presence ofabout 0.1 to 1% by weight of a substantially water-insoluble wax, about1 to 5% by weight of bentonite and about 5 to 20% by weight of urea.

16. A liquid detergent composition in the form of a stable, free-flowingsuspension in accordance with claim 15 wherein the wax is hydrogenatedcastor oil.

17. A liquid detergentcomposition in the form ofa 9 stable, free-flowingsuspension in accordance with claim 15 wherein the wax is carnauba wax.

18. A liquid detergent composition in the form of a substantiallyhomogeneous suspension having thixotropic properties consistingessentially of the following approximate formulation:

Ingredients: Percent Higher alkyl benzene sulfonate detergent 10-25Sodium tripolyphosphate 20-40 Wax 0.1-1 Bentonite 1-5 Urea 2-20 Ethylalcohol 5-20 Water 5-20 19. A liquid detergent composition in the formof a substantially homogeneous suspension in accordance with claim 18which contains about 1-15% by weight of a higher fatty aciddiethanolamide.

10 References Cited in the file of this patent UNITED STATES PATENTS2,486,921 Byerly Nov. 1, 1949 2,519,062 Miskel Aug. 15, 1950 2,581,677Machlis Jan. 8, 1952 2,607,740 Vitale Aug. 19, 1952 FOREIGN PATENTS401,413 Great Britain Nov. 16, 1933 461,221 Great Britain Feb. 12, 1937OTHER REFERENCES Gregory: Uses and Applications of Chemicals, pp. 85,629, 630 (1939).

Surface Active Agents, Schwartz and Perry, Interscience Publishers,Inc., N.Y. (1949), page 235.

